Python string-Class substring lookup function

The Python string class has a useful function that is handy for operations related to finding Python string type Object substrings, with the following APIs:

|   Find (...)|     S.find (Sub [, Start [, end]]), int|     |     inch  is found,|      is contained within S[start:end]. Optional|      and inch slice notation.|     |     Return-1 On Failure

Assume that S is a string object, call the Find function and pass in the substring of a substring or substring (that is, a slice of a substring from start to end) as a parameter.

The return value is of type int, and if S contains an incoming parameter sub, returns the index of the substring (substring) in the parent string (S), and returns 1 for the lookup index failure if the substring passed in as a parameter is not included.

Python string-Class substring lookup function